Article



Patented Jan. 26, 1943 UNE'E'ED STATES PATENT OFFICE ARTICLE Merrill L. Rathbun, Salamanca, N. Y.

Application January 12, 1940, Serial No. 313,552

2 Claims.

This invention relates to an improvement in manufactured articles comprised of two or more elements.

The invention, in one form, is applied to molded articles that are comprised of at least two elements. The elements are separately molded from any commercial plastic material and include corresponding parts that may be engaged in commen by suitable fastening or securing means.

Prior to this invention it has been the general practice in molding articles from plastic materials to 50 design such articles as to eliminate undercut surfaces and somewhat concealed cavities, for the reason that the molds required are not only of a complicated nature, and expensive to produce, but not satisfactory, since damage .to the molded article as well as the mold frequently occurs. Of course the purpose of undercut surfaces or cavities is to reduce the amount of material and weight, as well as improve the appearance and utility of a molded article. With the present demand for molded articles of all manner of design and utility it has become necessary to develop some method of manufacturing such articles without the use of complicated and expensive molds.

The present invention, by the elimination of complicated molds, makes practicable the molding of articles from plastic material with greater variety in design and utility, and this therefore constitutes one of the objects thereof.

Another object of the invention lies in the assembly of an article from two or more separate elements molded from suitable plastic material.

Another object of the invention makes practicable the separate production of two or more elements that, when joined together, form a complete article, or complete that portion of an article in a given form that was heretofore di-fiioult or impossible toproduce as a single element.

Another object of the invention lies in the provision of means for fixedly joining two or more separately produced elements of an article of manufacture.

Another object of the invention lies in the provision of an article comprised at least in part of two or more elements, separately molded from any suitable plastic material, that are permanently joined together.

Another object of the invention lies in the provision of an article of manufacture comprised in part of two or more molded plastic elements that are fixedly joined by means of drive fitted keys.

Other objects and advantages of the invention Will be more fully understood from a consideration of the following specification taken in com junction with the accompanying drawing; and in which Figure 1 is a perspective view of a two element article of manufacture embodying one form of the invention;

Figure 2' is a fragmentary plan view of the article shown in Figure 1, parts being broken away to illustrate certain of the structural details;

Figure 3 is an enlarged vertical sectional view taken substantially on the line 3-3 of Figure 2;

Figure 4 is another enlarged vertical sectional view taken substantially on the line 4-4 of Figure Figure 5 is a fragmentary elevational view taken in the direction indicated at 5-5 of Figure 4, parts being broken away to disclose the overlapping arrangement of certain of the parts; and

Figure 6 is an exploded view showing the elements of the article prior to assembly.

Reference is now had to the drawing wherein the, numeral I0 is employed to generally designate an article of manufacture to which the present invention is applied. The article illustrated takes the form of a tray that is comprised of a base I I and upright rim or wall member I2. The base shown is a flat rectangular member having a slight upwardly directed marginal flange I3. Spaced slightly inwardly from all four edges of the base, and in any desired duplicate arrangement, are pairs of upstanding lugs I4. Each pair of lugs forms an open ended transverse slot I6. It is evident that no problem is involved in the manufacture of a mold for producing the base I I, by reason of the simple structural details.

The rim member I2 may comprise interior upright walls I! that, at their upper edges, are integral with outwardly and downwardly curved walls I8. The lower edge I9 of the wall IB may seat on the base II adjacent flange I3. All four walls I! at suitable intervals may be formed with reinforced portions 2I that extend into the space 22 between walls I! and I8. At the lower edge of the wall I1, and centrally of each reinforced portion 2|, is an outwardly opening slot 23. When the member I2 is positioned on the base I I, slots 23 register with slots I6. From the foregoing it is evident that there are no cavities or undercuts that would require the use of a complicated mold for the manufacture of the member I2.

The assembly of article In from a pair of elements, such as the base I I and member I2, is as follows: The member I2 is positioned on the base II with the lower edge of the Wall I8 abutting flange l3. Small metal disks 24 are provided for the purpose of looking together the overlapping portions of the two elements of the article, namely, lugs l4 and portions 2|. These disks are of a width slightly greater than the width of slots 16 and 23 and are each formed with a sharp forward edge. When forced into the slots from the interior of the article, they cut their own groove in the plastic material of which the parts are formed. and serve to prevent relative displacement.

When the elements of the article In are assembled it will be noted that the space within the member [2 becomes a closed compartment and that it would be impossible to mold this article in a single piece. It is evident that the rim member l2 could be solid rather than hollow as shown, but this would involve a considerable increase in material and weight and would not be practical, in view of the tendency of fairly thick plastic articles to warp subsequent to being removed from a mold.

Although applicant has shown and described only one design of an article comprised of two separately manufactured elements and illustrated only one form of means for rigidly fixing the elements together, it is to be understood that the means of securement may be varied, as well as its application to articles of more than two elements and of different design, without departing from the spirit and scope of the invention as defined in the hereunto annexed claims.

Having thus set forth my invention, what I claim as new and for which I desire protection by Letters Patent is:

1. In an article of manufacture of the receptacle type having separate base and wall elements, upstanding portions on the base element spaced to provide slots, portions of the wall element having slots, interengageable means on said elements serving to align said slots when said elements are brought into abutment, and metallic disks having drive fit engagement with certain walls of the aligned slots, said disks being self-grooving in the walls of said slots and serving to secure said elements against relative displacement.

2. In an article of manufacture of the receptacle type having at least two separately produced wall elements, portions on each of said elements providing open-ended slots, interengageable means on said elements serving to align said lots when said elements are assembled, the walls of said slots being in overlapping arrangement, and means having self-grooving engagement with opposite walls of the slots of the assembled elements and being inserted into said slots at substantially right angles to the direction of assembly of said elements said opposite walls extending in the direction of assembly of the elements, the groove of one element being a substantial continuation of the groove of the other element.

MERRILL L. RATHBUN. 

